Experimental Modeling of Ankerite–Pyrite Interaction under Lithospheric Mantle P–T Parameters: Implications for Graphite Formation as a Result of Ankerite Sulfidation

Experimental modeling of ankerite–pyrite interaction was carried out on a multi-anvil high-pressure apparatus “split sphere” type (6.3 GPa, 1050–1550 °C, 20–60 h). At T ? 1250 the formation pyrrhotite, dolomite, magnesite, and metastable graphite established. higher temperatures, generation two immiscible melts (carbonate sulfide ones), as well crystallization diamond growth seeds, occurred. It established that decrease in iron concentration ankerite occurs by extraction leads to pyrrhotite or melt, with corresponding breakdown into dolomite magnesite. Further redox Ca,Mg,Fe carbonates (or between carbonate melts) results reduction C0 (±diamond seeds). interaction, which can occur downgoing slab, involves sulfidation triggers further graphite-forming reactions be one scenarios elemental carbon under subduction settings.